Mircea Voskerician says he agreed to sell his stake in the property to Mr Zuckerberg in exchange for a promise that Mr Zuckerberg would introduce him to other wealthy people who might want to buy homes. Mr Voskerician says Mr Zuckerberg never made those introductions.

His lawsuit, filed this month in Santa Clara County, claims breach of contract. The San Jose Mercury News reported the lawsuit Monday.

Mr Zuckerberg's attorney, Patrick Gunn, told the Mercury News his client paid Mr Voskerician $1.7 million for the right to buy the property. He says Mr Voskerician's lawsuit is meritless.